Throughout the broad sweep of human history, there are many examples of people, or classes of people, who chose to avoid the costs of parenthood. Indeed, falling fertility is a recurring tendency of human civilization. Why then did humans not become extinct long ago? The short answer is patriarchy.

Patriarchy does not simply mean that men rule. Indeed, it is a particular value system that not only requires men to marry but to marry a woman of proper station. It competes with many other male visions of the good life, and for that reason alone is prone to come in cycles. Yet before it degenerates, it is a cultural regime that serves to keep birthrates high among the affluent, while also maximizing parents' investments in their children. No advanced civilization has yet learned how to endure without it.

Through a process of cultural evolution, societies that adopted this particular social system -- which involves far more than simple male domination -- maximized their population and therefore their power, whereas those that didn't were either overrun or absorbed. This cycle in human history may be obnoxious to the enlightened, but it is set to make a comeback.

"It competes with many other male visions of the good life" - not just male visions, either. I know more than a few couples, now in their fifties, still toned and honed from the gym and swimming, leading a good life - the million-pound house, the boat, skiing three or four times a year - and no children. Lucky nephews and nieces, that's all I can say - unless the Cats Protection League gets the lot.

The long-term financing of social security schemes, private pension plans, and healthcare systems has little to do with people living longer. Gains in life expectancy at older ages have actually been quite modest, and the rate of improvement in the United States has diminished for each of the last three decades. Instead, the falling ratio of workers to retirees is overwhelmingly caused by workers who were never born. As governments raise taxes on a dwindling working-age population to cover the growing burdens of supporting the elderly, young couples may conclude they are even less able to afford children than their parents were, thereby setting off a new cycle of population aging and decline.

Yup. As I've noted before, the stinky rich and the tax-funded poor can sprog away as much as they like. It's Mr and Mrs Average who've found that 2.4 kids doesn't go with a mother who needs to work full time to pay the bills.

the percentage of women born in the late 1930s who remained childless was near 10 percent. By comparison, nearly 20 percent of women born in the late 1950s are reaching the end of their reproductive lives without having had children. The greatly expanded childless segment of contemporary society, whose members are drawn disproportionately from the feminist and countercultural movements of the 1960s and 70s, will leave no genetic legacy. Nor will their emotional or psychological influence on the next generation compare with that of their parents.

While I'm continually bemoaning the malign influence of Sixties culture on our children, the point is that the influence, while real, was almost wholly negative - destructive of the existing culture. We aren't bringing up a race of young hippie Aquarians, if the assault, knife crime and mental illness stats tell us anything at all.

Nearly a quarter of the children of baby boomers descend from the mere 11 percent of baby boomer women who had four or more children. These circumstances are leading to the emergence of a new society whose members will disproportionately be descended from parents who rejected the social tendencies that once made childlessness and small families the norm. These values include an adherence to traditional, patriarchal religion, and a strong identification with one's own folk or nation. This dynamic helps explain, for example, the gradual drift of American culture away from secular individualism and toward religious fundamentalism. Among states that voted for President George W. Bush in 2004, fertility rates are 12 percent higher than in states that voted for Sen. John Kerry.

Excellent news for a father of four. But in the UK context, "parents who rejected the social tendencies that once made childlessness and small families the norm" will increasingly mean Muslim parents. Remember these stats.

white 1.8Afro-Caribbean 1.8Indian 2.3Pakistani 4.0Bangladeshi 4.7

(I noted from the coverage of the murder of poor Abdo Sa’eed al-Selwi in Liverpool that he had either 11 or 12 children - the papers didn't agree.)

In almost all the hunter-gatherer societies that survived long enough to be studied by anthropologists, such as the Eskimos and Tasmanian Bushmen, one finds customs that in one way or another discouraged population growth. In various combinations, these have included late marriage, genital mutilation, abortion, and infanticide. Some early hunter-gatherer societies may have also limited population growth by giving women high-status positions. Allowing at least some number of females to take on roles such as priestess, sorcerer, oracle, artist, and even warrior would have provided meaningful alternatives to motherhood and thereby reduced overall fertility to within sustainable limits.

During the eons before agriculture emerged, there was little or no military reason to promote high fertility. War and conquests could bring little advantage to society. There were no granaries to raid, no livestock to steal, no use for slaves except rape. But with the coming of the Neolithic agricultural revolution, starting about 11,000 years ago, everything changed. The domestication of plants and animals led to vastly increased food supplies. Surplus food allowed cities to emerge, and freed more people to work on projects such as building pyramids and developing a written language to record history. But the most fateful change rendered by the agricultural revolution was the way it turned population into power. Because of the relative abundance of food, more and more societies discovered that the greatest demographic threat to their survival was no longer overpopulation, but underpopulation.

Patriarchal societies come in many varieties and evolve through different stages. What they have in common are customs and attitudes that collectively serve to maximize fertility and parental investment in the next generation. Of these, among the most important is the stigmatization of "illegitimate" children. One measure of the degree to which patriarchy has diminished in advanced societies is the growing acceptance of out-of-wedlock births, which have now become the norm in Scandinavian countries, for example.

Under patriarchy, "bastards" and single mothers cannot be tolerated because they undermine male investment in the next generation. Illegitimate children do not take their fathers' name, and so their fathers, even if known, tend not to take any responsibility for them. By contrast, "legitimate" children become a source of either honor or shame to their fathers and the family line. The notion that legitimate children belong to their fathers' family, and not to their mothers', which has no basis in biology, gives many men powerful emotional reasons to want children, and to want their children to succeed in passing on their legacy. Patriarchy also leads men to keep having children until they produce at least one son.

Another key to patriarchy's evolutionary advantage is the way it penalizes women who do not marry and have children. Just decades ago in the English-speaking world, such women were referred to, even by their own mothers, as spinsters or old maids, to be pitied for their barrenness or condemned for their selfishness. Patriarchy made the incentive of taking a husband and becoming a full-time mother very high because it offered women few desirable alternatives ...

Under patriarchy, maternal investment in children also increases. As feminist economist Nancy Folbre has observed, "Patriarchal control over women tends to increase their specialization in reproductive labor, with important consequences for both the quantity and the quality of their investments in the next generation." Those consequences arguably include: more children receiving more attention from their mothers, who, having few other ways of finding meaning in their lives, become more skilled at keeping their children safe and healthy. Without implying any endorsement for the strategy, one must observe that a society that presents women with essentially three options -- be a nun, be a prostitute, or marry a man and bear children -- has stumbled upon a highly effective way to reduce the risk of demographic decline.

Another Laban theme - the normalisation of bastardy. However, far from not being encouraged, the production of bastards is one of the most heavily taxpayer-subsidised industries in the UK - and contrary to received libertarian economic theory, production has increased something like eight-fold in the last 40 years, making bastards a real British success story. I'm not sure Prof Longman has taken this into account - but on the other hand, underclass males are the storm-troopers of patriarchy (parental advisory) in their relationships with the tender sex. In Robert Whelan's words :

"We have created the classic conditions for the emergence of a warrior class: separation of economic activity from family maintenance; children reared apart from fathers; wealth subject to predation; and male status determined by combat and sexual conquest."

I digress.

Often, all that sustains the patriarchal family is the idea that its members are upholding the honor of a long and noble line. Yet, once a society grows cosmopolitan, fast-paced, and filled with new ideas, new peoples, and new luxuries, this sense of honor and connection to one's ancestors begins to fade, and with it, any sense of the necessity of reproduction. "When the ordinary thought of a highly cultivated people begins to regard 'having children' as a question of pro's and con's," Oswald Spengler, the German historian and philosopher, once observed, "the great turning point has come."

Yet that turning point does not necessarily mean the death of a civilization, only its transformation. Eventually, for example, the sterile, secular, noble families of imperial Rome died off, and with them, their ancestors' idea of Rome. But what was once the Roman Empire remained populated. Only the composition of the population changed. Nearly by default, it became composed of new, highly patriarchal family units, hostile to the secular world and enjoined by faith either to go forth and multiply or join a monastery. With these changes came a feudal Europe, but not the end of Europe, nor the end of Western Civilization.

This is where the whole thing gets a bit too optimistic.

In Europe today, for example, how many children different people have, and under what circumstances, correlates strongly with their beliefs on a wide range of political and cultural attitudes. For instance, do you distrust the army? Then, according to polling data assembled by demographers Ronny Lesthaeghe and Johan Surkyn, you are less likely to be married and have kids-or ever to get married and have kids-than those who say they have no objection to the military. Or again, do you find soft drugs, homosexuality, and euthanasia acceptable? Do you seldom, if ever, attend church? For whatever reason, people answering affirmatively to such questions are far more likely to live alone, or in childless, cohabitating unions, than those who answer negatively.

The great difference in fertility rates between secular individualists and religious or cultural conservatives augurs a vast, demographically driven change in modern societies. Consider the demographics of France, for example. Among French women born in the early 1960s, less than a third have three or more children. But this distinct minority of French women (most of them presumably practicing Catholics and Muslims) produced more than 50 percent of all children born to their generation, in large measure because so many of their contemporaries had one child or none at all.

Many childless, middle-aged people may regret the life choices that are leading to the extinction of their family lines, and yet they have no sons or daughters with whom to share their newfound wisdom. The plurality of citizens who have only one child may be able to invest lavishly in that child's education, but a single child will only replace one parent, not both. Meanwhile, the descendants of parents who have three or more children will be hugely overrepresented in subsequent generations, and so will the values and ideas that led their parents to have large families.

Yes.. but .. in Europe lets say you have the nice liberal Guardianista/feminists and those good-timers who can't be fagged with the whole children thing - no kids, the religious natives and the native underclass - 3 kids - and the religious incomers - 4 kids. Given that natives are in the UK currently nearly 90% of the population (but less than 77% of the children), the die-off of the childless baby boomers is going to leave a different landscape, in which (IMHO) the religious incomers will make a far more cohesive group, and probably a larger one, than the religious natives.

Tomorrow's children, therefore, unlike members of the postwar baby boom generation, will be for the most part descendants of a comparatively narrow and culturally conservative segment of society. To be sure, some members of the rising generation may reject their parents' values, as always happens. But when they look around for fellow secularists and counterculturalists with whom to make common cause, they will find that most of their wouldbe fellow travelers were quite literally never born.

I agree. I'm just not sure that the "narrow and culturally conservative segment of society" will be crusty Laban-style Christians.

The rollback of the welfare state forced by population aging and decline will give these elements an additional survival advantage, and therefore spur even higher fertility. As governments hand back functions they once appropriated from the family, notably support in old age, people will find that they need more children to insure their golden years, and they will seek to bind their children to them through inculcating traditional religious values akin to the Bible's injunction to honor thy mother and father.

Societies that are today the most secular and the most generous with their underfunded welfare states will be the most prone to religious revivals and a rebirth of the patriarchal family.

That's the rub. How will people who've paid taxes all their lives respond when they're told that the old social contract has been torn up ? But I still see that people with a living tradition of family self-help are likely to cope better with such a scenario than those who've been conditioned to wait for 'someone' to 'do something'. The Lord does indeed help those who help themselves.